根系是植物生存之本,它对植物不仅起固持和吸收水分、养分的作用,而且还具有重要的合成功能,如合成某些植物激素、烟碱、氨基酸、酰胺等物质,许多植物的硝酸盐还原是在根中进行,根可合成数量足以在植物的木质部汁液中察觉的细胞分裂素和赤霉素。有人推测,在寒冷、干燥、水分饱和的或盐碱的土壤中,植物生长不良的部分原因可能是由于通常在根中合成的生长调节物质对枝条的供给减少所致。由此可见,植物根系对地上部分的生长起着重要的生理作用。一、根际营养在多年生本本植物中,除了根尖以上分生组织和根毛对水分、养分有吸收功能外,植物体中有相当部份水分、养分的吸收是通 The root system is the basis of plant survival. It not only plays a role of holding and absorbing moisture and nutrients, but also has important synthetic functions such as synthesizing certain plant hormones, nicotine, amino acids, amides and many other plant nitrates The reduction is carried out in the roots, and the roots can synthesize cytokinin and gibberellins in quantities sufficient to be detected in the xylem juice of the plant. It has been speculated that in cold, dry, saturated or salty soils, the poor growth of plants may be due in part to the reduced supply of shoots to growth regulators which are usually synthesized in the roots. Thus, plant roots play an important physiological role in the growth of aerial parts. First, the rhizosphere nutrition In perennial plants, in addition to the apical meristem and root hair above the moisture, nutrient absorption, the plant has a considerable part of the water absorption of nutrients is through